Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Em qual rodada Al Unser venceu no Wisconsin State Fair Park Speedway?
 ###Tabelas: CREATE TABLE schedule_and_results (schedule_and_results_id AUTO_INCREMENT PRIMARY KEY, Rnd INT, Date VARCHAR, Race Name VARCHAR, Length VARCHAR, Track VARCHAR, Location VARCHAR, Pole Position VARCHAR, Winning Driver VARCHAR) CREATE TABLE main_songlist (main_songlist_id AUTO_INCREMENT PRIMARY KEY, Track INT, Song Title VARCHAR, Artist VARCHAR, Album VARCHAR, Legends Track? VARCHAR) CREATE TABLE tour_de_france (tour_de_france_id AUTO_INCREMENT PRIMARY KEY, Height (m.) VARCHAR, No. of times visited INT, No. of HC climbs INT, First time as HC climb INT, Most recent INT) CREATE TABLE singles:_10_7_titles_3_runner-ups (singles:_10_7_titles_3_runner-ups_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Year INT, Championship VARCHAR, Surface VARCHAR, Opponent in the final VARCHAR, Score in the final VARCHAR) CREATE TABLE augmented_seventh_chord_table (augmented_seventh_chord_table_id AUTO_INCREMENT PRIMARY KEY, Chord VARCHAR, Root VARCHAR, Major third VARCHAR, Augmented fifth VARCHAR, Minor seventh VARCHAR)  
SELECT MIN Rnd FROM schedule_and_results WHERE Winning Driver = Al Unser AND Track = Wisconsin State Fair Park Speedway